Constellation: Reticulum the Astronomical Reticle

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Greek:Reticulum ('Reticle')
Genitive:Reticuli
Short form:Ret
Area:114 sq deg
Co-ordinates1:04h,-60°
Origin:Modern

So what is a reticle? It is from the Latin for net and is an overlay bearing a grid of fine lines and is used to mark or measure positions.
Reticulum
is best seen by observers in the Southern Hemisphere. It makes its highest appearance in November. The constellation is bordered by
Horologium
,Dorado
, and Hydrus.

History

Before Reticulum was first drawn, an earlier constellation by the astronomer Isaac Habrecht II(1589-1633)2 stood in this position. Nicolas Louis de Lacaille(1713-1762) set up an observatory in South Africa where he worked in 1751-1753. At that observatory he used a rhomboidal reticle. He named this constellation 'le reticle romboide' in honour of this instrument. Reticulum does not have any myths because it is a modern constellation.

Stars

Johannes Bayer set up the current system of calling the brightest star alpha and then proceeding down the Greek alphabet for subsequent stars. The combination of this letter with the genitive of the constellation is known as the 'Bayer Designation'. Many dimmer stars such as HD 27894 have neither a name nor a Bayer Designation.

Gamma Reticuli varies slightly in the space of 25 days. Its magnitude varies between +4.42 and +4.61

Star Table

StarDesignationName or

catalogue number
MagnitudeDistance

(light years)
Spectral classification
and/or comments
α RetAlpha HR1336+3.35250G8
β RetBeta HR1175+3.8578K1
γ RetGamma HR1264+4.513490M4
δ RetDelta HR1247+4.56530M2
ε RetEpsilon HR1355+4.4459K2
ζ-1 RetZeta1HR1006+5.5440G2
ζ-2 RetZeta2HR1010+5.2440G2
η RetEta HR1395+5.24380G8
θ RetTheta HR1372+5.87462B9
ι Retiota HR1266+4.9747K4
κ RetKappa HR1083+4.7270F5
---unnamed HD27894+9.20138K2

Deep Sky Objects

NGC 1313
is a barred spiral galaxy 15mly away. Observed at shorter wavelengths it is more ordered than in visible light, and exhibits signs of being rich in hydrogen which would make it a nursery for new stars.

The New General Catalogue, by J Dreyer, was published by the Royal Astronomical Society in the late 19th Century. It was expanded to include two Index Catalogues (IC). This list of star clusters, nebulae and galaxies was revised again in 1973, and is continually updated by the NGC/IC Project.

Cat. NO.Type of ObjectBrightness (m)Distance

(mega-ly)
NGC 1313 galaxy +9.215
NGC 1536 galaxy+12.754
NGC 1543galaxy +10.352
NGC 1574 galaxy +10.7 47
IC 2037galaxy +14.7364
IC 2049galaxy+14.565
IC 2056 galaxy+12.550
IC 2060galaxy+15.17294

Extrasolar Planets

Here are some planetary systems that have been found in this constellation. The size of these extrasolar planets is compared to the mass of Jupiter. This is known by astronomers as the 'Jovian scale'.


the Star HD 27894 has a proper motion about 26% of Barnard's Star. There have been claims that it has planets at 0.07, 0.12, and 0.41 Astronomical Units, however, only the one at 0.12 AU (HD 27894b) has been confirmed.

Star name or

catalogue number
Planet

catalogue number
Planet mass

(Jovian scale)
Distance
(AU)
Orbital period

(Earth days)
Epsilon ReticuliHD27442b1.281.18423.8
HD23079HD23079b2.611.16738.45
HD23127HD23079b1.52.401,214
HD27894HD27894b0.620.1218.0
Zeta2 ReticuliHD20807b
4
0.270.1418.9

Ufology

It may be a hoax, a delusion, or a hidden truth; but there are those who believe that we have been visited by beings from Zeti2 Reticuli. In 1961 two people in New Hampshire saw an object in the sky. They claim they stopped the car and the husband trained a pair of binoculars on the object. The next thing they know (according to their testimony) it is two hours later. Under hypnosis the story emerges that they were taken aboard a UFO and the woman was shown a map. The stars on the map were not labelled. The map she said she saw was three dimensional. The one she drew under hypnotic regression was not. The Boston Psychiatrist5 who examine her and her husband concluded that the story was not a fabrication. It was several years before any star names were added to this map. A tentative map was drawn up by an amateur astronomer in Ohio, connecting it to the star Zeta2Reticuli, and then a professor at OSU6 had his students enter star locations in a computer and generated a map. Finally Mark Steggert of the University of Pittsburgh used a program he had written and the maps were compared. This whole incident was written up in the December 1974 issue of Astronomy magazine.


Four decades later, following the death of her husband, the woman still believes that she was taken aboard a UFO
by extra-terrestrials
and that the star system from which her abductors came was Zeta2  Reticuli. In 1995 a group of extrasolar planets was listed in the Extrasolar Planet Encyclopedia including Zeta2 Reticuli. However, when the link to ufology was realized the listing was rejected giving as the reason: 'the data may have been misinterpreted'.

1Current IAU guidelines use a plus sign (+) for northern constellations and a minus sign (−) for southern ones.2Grandson of clockmaker Isaac Habrecht (1544-1620).3 Slightly variable.4After being published for four days authorities disavowed the existence of this planet.5Benjamin Simon.6 Ohio State University.

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